Method for making aromatic ethers using diorganoamino pyridinum salt catalyst

Abstract

A method is provided for making aromatic ethers by effecting the displacement of reactive radicals on an activated aromatic nucleus such as a phthalimide with a mono or bisalkali metal phenoxide in the presence of an organic solvent and a dialkylamino branched alkyl substituted pyridinium salt as a phase transfer catalyst. Improved yields of bis(aromatic ethers) are achieved without the production of undesirable by-products, such as alkylated phenols.

What we claim as new and desire to secure by Letters Patent of the United States is: 
     
       1. In the method for making an aromatic ether comprising the reaction between a nuclear activated aromatic compound substituted with a leaving group selected from a nitro or halo radical and an alkali metal phenoxide in the presence of a phase transfer catalyst, the improvement which comprises utilizing as the phase transfer catalyst a diorganoaminopyridinium salt of the formula, ##STR9## where R 2  and R 3  are monovalent or divalent organo radicals selected from C.sub.(1-13) hydrocarbon radicals and C.sub.(1-13) substituted hydrocarbon radicals and C.sub.(1-8) divalent alkylene radicals which can be part of a cyclic structure forming a C.sub.(4-12) ring, R 4  is selected from C.sub.(4-18) linear or branched alkyl radicals and Y is a counter ion. 
     
     
       2. A method in accordance with claim 1, where the nuclear activated aromatic compound is a nuclear substituted phthalimide. 
     
     
       3. A method in accordance with claim 1, where the alkali metal phenoxide is the disodium salt of bisphenol-A. 
     
     
       4. A method in accordance with claim 1, where the diorganoaminopyridinium salt is N-neopentyl-4-(4-methylpiperidinyl)pyridinium chloride. 
     
     
       5. A method in accordance with claim 1, where the diorganoaminopyridinium salt is N-neopentyl-4-dibutylaminopyridine. 
     
     
       6. A method in accordance with claim 1, where the diorganoaminopyridinium salt is N-neopentyl-4-dihexylaminopyridine. 
     
     
       7. A method for making aromatic etherimides of the formula ##STR10## which comprises, (A) heating a substituted phthalimide of the formula ##STR11##  and an alkali metal phenoxide salt of the formula   (R.sup.1 --OM).sub.a      in the presence of organic solvent and an effective amount of a phase transfer catalyst of the formula ##STR12## (B) agitating the resulting mixture with a precipitating or extractive organic solvent for the resulting aromatic etherimide, or allowing the mixture to cool and   (C) recovering the aromatic ether imide from the mixture of (B) where R is a monovalent radical selected from hydrogen, a C.sub.(1-8) alkyl radical and C.sub.(6-13) aryl radical, R 1  is a C.sub.(6-30) aromatic organic radical, where R 2  and R 3  are monovalent or divalent organo radicals selected from C.sub.(1-13) hydrocarbon radicals and C.sub.(1-13) substituted hydrocarbon radicals and C.sub.(1-8) divalent alkylene radicals which can be part of a cyclic structure forming a C.sub.(4-12) ring, R 4  is selected from C.sub.(4-18) linear or branched alkyl radicals and Y is a counter ion, M is an alkali metal ion, X 1  is a radical selected from nitro and halo, and a is an integer equal to 1 to 2, and when a is 1, R 1  is monovalent and when a is 2, R 1  is divalent.     
     
     
       8. A method in accordance with claim 7, utilizing an alkali metal monophenoxide salt. 
     
     
       9. A method in accordance with claim 7, utilizing an alkali metal diphenoxide salt. 
     
     
       10. A method in accordance with claim 7, where the alkali metal salt is the anhydrous disodium salt of bisphenol-A. 
     
     
       11. A method in accordance with claim 7, where the alkali metal phenoxide salt is made by azeotroping water from a mixture of toluene and the hydrated form of the alkali metal phenoxide salt. 
     
     
       12. A method in accordance with claim 7, where the alkali metal phenoxide salt is formed in situ from an aqueous mixture of the alkali metal hydroxide and the corresponding phenol. 
     
     
       13. A method in accordance with claim 7, where the alkali metal phenoxide salt is made from a mixture of an alkali metal alkoxide and the corresponding monohydric or dihydric phenol. 
     
     
       14. A method in accordance with claim 7, where the substituted phthalimide is 3-nitro-N-methylphthalimide. 
     
     
       15. A method in accordance with claim 7, where the substituted phthalimide is 4-fluoro-N-methyl or N-phenyl phthalimide. 
     
     
       16. A method in accordance with claim 7, where the substituted phthalimide is 4-nitro-N-methyl or N-phenyl phthalimide. 
     
     
       17. A method in accordance with claim 7, where the alkali metal phenoxide is an alkali bisphenoxide of a dihydric sulfone. 
     
     
       18. A method in accordance with claim 7, where the alkali metal phenoxide is an alkali bisphenoxide of a dihydric sulfide.